The cost of operating the Maintenance Department is to be allocated to four production departments based on the floor space each occupies. Department A occupies $1000m^2$; Department $B,600m^2$; Department C$,1100m^2$; and Department D$,400m^2.$ If the July cost was $$27,900,$ how much of the cost of operating the Maintenance Department should be allocated to each production department?

The operating cost for Department A is$?$

The operating cost for Department B is$?$

The operating cost for Department C is$?$

The operating cost for Department D is$?$

$($Simplify your answer.$)$